In which scenario is work being done on an object? a) A force is applied to an object to hold it at rest on an inclined plane.
b) Sitting on a box.
c) An upward force is applied to an object to move it upward at a constant speed.
d) An upward force is applied to an object to suspend it motionless in mid-air.

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?